The present invention deals with the improvements introduced in a pneumatic propulsion system for freight and/or passenger vehicles, which aim to enhance its constructive and functional features, ensuring this system a highly favorable performance in the transportation of freight and/or passengers.
The state-of-the-art, taken as reference for the insertion of the improvements described in this report, is represented by the pneumatic propulsion system for freight and/or passenger vehicles according to the Brazil Patent of Invention nbr. 7703372 deposited on the 25 th of May of 1977 characterized by comprising a tube having a longitudinal slit with a sealing system, a pylon, attaching a propelling fin assembly that travels in the tube to the frame of a vehicle that is supported by the tube, said pylon sliding through the longitudinal slit, propulsion being effected by means of a high-speed airflow acting on the blocking surface of the propelling fin moving it and consequently setting the vehicle into motion on devices adequate to support such motion, said airflow being generated by stationary air sources positioned outside the vehicle. Said system vehicle is provided with brakes that act directly on the motion-support devices and its tube is outfitted with conduits for telephone lines. The pneumatic system so described is characterized by pneumatic propulsion of vehicles from stationary units, and the system objectives are as follows: to provide an urban transportation system dimensioned to cater for today's and future needs; to make compatible under one unique concept optimum features for vehicles, trackway and terminals, to achieve significant advances in economics, speed, regularity, comfort and safety at low cost.
Also known as state-of-the-art are first improvements introduced in the pneumatic transportation system for freight or passenger vehicles in accordance with the Brazil Patent of Invention nbr. 7906255 deposited on the 28th of Sept. of 1979, characterized by having a propulsion duct which besides channelling air for vehicle propulsion additionally provides the structure required to install an elevated trackway, that is, the structure of the propulsion duct itself embodies an elevated trackway with integrally attached rails, thereby doing away with any other rail support structures, except for structures spaced at intervals wide enough so not as to interface with surface traffic that support or hold the entire structure above ground. A part of said system provisions are made to seal the longitudinal slit in the duct, when suction is applied to the duct, said differential pressure acting on a flexible seal and pressing it against a stop, allowing at same time passage of the propulsion pylon by mechanical displacement of the elastic flap, said elastic flap also allowing for sealing in overpressure, a pressure relief system also being provided. Said system incorporates a flow alternator close to each air blower unit which, in combination with a flow control valve provides control over any airflow condition in the duct, thus determining vehicle movements by remote control. Said system comprises a set of valves at each terminal arranged to ensure means of control for a safety system that guarantees positive separation of vehicles under any circumstances, overall system being under control of one operator and/or an automatic control system located at each station. The perfected automatic propulsion system for transportation of cargo and/or passengers as described above and which is characterized by pneumatic propulsion of vehicles from stationary airflow generating units, has the following basic objectives:
1. Provide an elevated trackway for transportation vehicle traffic, said way having least possible dimensions for a given transport capacity, aiming at low building and installation costs, and minimum environmental impact.
2. To achieve extremely light and simple transportation vehicles, free of any propulsion equipments, the low weight of which will require little energy for accelerating and braking and impose a low stress level to the trackway, aiming also at simple construction and maintenance, low operating costs and high reliability.
3. Provide a vehicle propulsion system that is stationary, aiming at low vehicle weight, low maintenance costs, high reliability, minimum environmental pollution.
4. Provide a pneumatic propulsion system that does not engage vehicular wheels, effecting vehicle traction by means of a device that is independent of the wheels, with the objective of overcoming the limitations imposed by wheel/rail systems on the performance of rail transport vehicles. And, lastly,
5. To effect the integration of all elements in a freight and/or passenger transportation system on an elevated way, silent, non-pollutant, adequate for installation over streets of urban centers, with low investment, low operating costs, high reliability and safety and high transport capacity.